An NBA source told the Globe that the Celtics have signed swingman Terrence Williams to a 10-day contract — and there’s a chance that Williams, who is heading here from China, could be in uniform when the Celtics face the Nuggets Tuesday.

Williams wasn’t with the team during its practice Monday. He is awaiting a clearance letter from the team he was playing for in China before he flies here, the source said.

Rivers said he wasn’t sure if Williams, who has played for three NBA teams, would be with the Celtics for their shootaround Tuesday morning. He did say that Williams worked out with the Celtics during the summer and that he “did a pretty good job.”

What impressed Rivers from that workout?

“He’s been in the league; that’s what impressed me,” said Rivers, who downplayed his comments on Williams because the signing isn’t official.

While the Celtics clearly need guards after losing Rajon Rondo and Leandro Barbosa, Williams, an athletic 6-foot-6-inch wing player, gives them a much-needed body, which, considering the heavy minutes everyone is playing, is a vital addition in itself.

i like this signing williams is like courtney lee but way more athletic ... i know why he cant stick to a team because of him being a head case. i dont think that will be a problem here... If i were to choose between him terry and barbosa i would go with williams..